Another Stutterer

[Soapy]

[quote author=Dcock link=topic=8360.msg82373#msg82373 date=1371572435]
[quote author=darrsi link=topic=8360.msg82372#msg82372 date=1371572097]
[quote author=Dcock link=topic=8360.msg82371#msg82371 date=1371571513]
[quote author=darrsi link=topic=8360.msg82359#msg82359 date=1371568406]
[quote author=Dcock link=topic=8360.msg82346#msg82346 date=1371563303]
Just to clarify, when the bike is cold, if you go full throttle it will go up the rev range fine with no stuttering? But once the bike is warm it will stutter as soon as you give it full throttle? Are you using choke when it's cold? If not put some choke on when its cold and then give it full throttle. If it stutters, then this may point towards over fuelling or not enough air  as the problem when the engine is up to temperature. Also you can test this again by seeing if putting choke on when the bike is hot makes the stutter worse. Let us know what happens when you try this. Cheers.

Stuttering, or bogging down can be caused by too much air!
Happened to my bike when one of the carb rubbers folded in on itself when my mechanic refitted them, and number 3 inlet rubber was letting air in.
Everytime i went to overtake or generally give the throttle a bit of welly it would splutter all over the place and bog down.
I had to have the bike in elsewhere to get them to look at my carbs and they showed me what they found.
[/quote]

yeah true too lean mixture will do that as well. If that is case here, when he puts the choke on during the warm ride it should make the stuttering less noticeable as he would be increasing the fuel to air mixture. Either way wacking the choke on will hopefully show us something.. or nothing maybe.. Although if it was too lean that would cause idle hunting and make it difficult to start as well? Which I don't think he has mentioned. It will be interesting to see what's causing this!
[/quote]
Not necessarily, i only noticed problems when opening the throttle right up, idle was fine and if i rode the bike easily there wasn't really an issue.
I even had 3 mechanics ride it and "they say" that they couldn't feel anything wrong, but obviously i ride the thing every day and knew damn well it wasn't right.
It cost me a fortune to get that sorted. As the carbs were off and i was booked into PDQ already i told him he may as well clean them up while i was there.  :'(
[/quote]
Damn, that doesn't sound fun at all. did you need a new carb rubber or jus reposition the old one?
[/quote]


It was literally just folded over in on itself by about an inch, he showed me it first then just unfolded it.
As it was number 3 carb it would never have have been seen or noticed unless it was removed, and i don't know how big the gap was letting air in, but i s'pose any air at all will make it misbehave.
It was accidental and just one of those things, BUT, i was really disappointed that 3 very experienced people couldn't feel the problem because quite frankly it was bloody obvious that it wasn't right in my opinion!
I went back to them 3 or 4 times then gave up wasting my time and took it to PDQ instead.
[/quote]
Hi Darrsi. My bike was doing it before I removed the carbs. I have given the inlet rubbers a look and there isn't any sign of cracking etc. It looks like I may be taking the carbs of again. If i do I'm going to take the inlet and airbox rubbers off for close inspection.
I'll report back tomorrow. Thanks again everybody.

[darrsi]

I very rarely need to use the choke, but if you use it regularly is it possible that it could be stuck on a little bit rather than being totally switched off?

[Soapy]

Spent a bit more time on the bike today. Ran it for nearly five miles with no issues. Whilst it was ok tried putting the choke on to see if it made any difference. It didn't. Tried going down to 3000 revs several times and every time it picked up ok. Got to about 5 miles and she started to play up. Pulling any more than 1/4 throttle resulted in severe stuttering. Tried putting on the choke whilst the stuttering was happening, didn't make any difference. Road her home.
Replaced fuel filter and a friend lent me a set of vacuum gauges to check the carb balance. Had to adjust 3 & 4 ever so slightly. Bike was now getting hot and fan was running as expected. Blipping the throttle when the bike is hot results in a little stutter as you flick the throttle.
After the balance I thought I would remove No's 1 & 4 Diaphragms. They look and feel fine. The rubber is soft and supple and no signs of holes. I also removed the plugs and apart from being very slightly black they were fine.
After I had put everything back to together the bike had cooled down a bit. I started her up and blipped the throttle without any real sign of the stutter. Got to be heat/time related.
I'm now leaning more to an ignition or some kind of electrical fault. If it was a carb/jets/diaphragm issue then surely it would occur from the start.
What effect would a pick up sensor breaking down/overheating have?
Have a short couple of video's I took on my Iphone of the carb balance but don't know how to load them.

[unfazed]

Check the rubber plugs on the vacuum take of points as they can crack and go unnoticed.
Check the wires to the pickup where it enters the alternator cover.
It is good idea is to take all connectors apart and spray with WD40 while checking for chaffed wiring.
A common place for corrosion is on the fuel pump connector and the pickup up connector.

[Soapy]

Check the rubber plugs on the vacuum take of points as they can crack and go unnoticed.
Check the wires to the pickup where it enters the alternator cover.
It is good idea is to take all connectors apart and spray with WD40 while checking for chaffed wiring.
A common place for corrosion is on the fuel pump connector and the pickup up connector.

Hi Unfazed. I checked the Vacuum plugs when I did the carb balance. They look ok. Visually checked the loom from the Pick Up Coil we're it comes out of the LH Engine Cover. Also had a look at the connectors under the LH side cover. Nothing obvious there.
The Haynes manual states if you want to replace the pick up coil as its part of the Alternator it has to be replaced as well. Need to be sure it's the problem as that will not be cheap to buy.

[Soapy]

I'm thinking of buying a replacement coil to hang in whilst fault finding. I believe a cheaper and better mod is to fit NGK plug caps to the leads. Can anybody tell me which ones i need to buy for my 600 2003. Also has anybody bought an aftermarket coil. Cheers John S

[red98]

Spent a bit more time on the bike today. Ran it for nearly five miles with no issues. Whilst it was ok tried putting the choke on to see if it made any difference. It didn't. Tried going down to 3000 revs several times and every time it picked up ok. Got to about 5 miles and she started to play up. Pulling any more than 1/4 throttle resulted in severe stuttering. Tried putting on the choke whilst the stuttering was happening, didn't make any difference. Road her home.
Replaced fuel filter and a friend lent me a set of vacuum gauges to check the carb balance. Had to adjust 3 & 4 ever so slightly. Bike was now getting hot and fan was running as expected. Blipping the throttle when the bike is hot results in a little stutter as you flick the throttle.
After the balance I thought I would remove No's 1 & 4 Diaphragms. They look and feel fine. The rubber is soft and supple and no signs of holes. I also removed the plugs and apart from being very slightly black they were fine.
After I had put everything back to together the bike had cooled down a bit. I started her up and blipped the throttle without any real sign of the stutter. Got to be heat/time related.
I'm now leaning more to an ignition or some kind of electrical fault. If it was a carb/jets/diaphragm issue then surely it would occur from the start.
What effect would a pick up sensor breaking down/overheating have?
Have a short couple of video's I took on my Iphone of the carb balance but don't know how to load them.

hi soapy......agree with you about the electrics  ,those diaphrams look fine,worth checking as you can now cross off you list of "possible stuttering causes"......iam just about to replace the pick up coil on mine,should be done this weekend as it looks like iam not working now (bl**dy weather)...will let you know how it go`s.......did check mine with a multimetre a while ago now and it checked out fine,this was checked with engine off ,not sure if you can check with engine running and at stuttering speed ......will have a think about that.

[darrsi]

I'm thinking of buying a replacement coil to hang in whilst fault finding. I believe a cheaper and better mod is to fit NGK plug caps to the leads. Can anybody tell me which ones i need to buy for my 600 2003. Also has anybody bought an aftermarket coil. Cheers John S

NGK SD05F, the straight ones.

http://www.ebay.co.uk/itm/1x-NGK-Resisto...125wt_1199

[Soapy]

Sussed at last. Rode the bike today for 10 miles with no issues. Then 5th gear 3000 revs and the dreaded stuttering started again. So for a couple of miles I thrashed her and then went to 3000 revs and pulled open the throttle really bad now. Pulled over to look around the bike to look for any clues. EUREKA!!! I was bending down on the left hand side when I heard a ticking sound. Looking closer and there was mega amount of sparking from the bottom rubber on No1 spark plug cap. People must have thought I was nuts as I was dancing around my bike at the side of the road. I pulled the rubber off and inspected the bottom of the cap for cracks. None obvious but I put it back on without the rubber. Started the bike up no sparks. Rode it for 20 miles, slowing down loads of times to less than 3000 revs and opened the throttle with no stuttering. Hurray. New NGK plug caps on order. darssi thanks for the info.
Is there a difference between SD05F and SD05FM (I was given this number by a bike dealer on the phone when I asked them which ones I needed for my bike).
Thanks to everybody for there guidance and input. I've learnt a hell of a lot about my bike from you guys and really appreciate it.
I did take a short video on my phone but don't think I can upload. But did take a picture and you can just see a spark on the rubber. In real time there were sparks everywhere.

[Soapy]

Just been on ebay. Seen the difference. The FM ones seem to be longer and cost a lot more. I'll think I'll go for the darrsi option.
http://www.ebay.co.uk/itm/NGK-SPARK-PLUG...4171f26946
would these be an option.
http://www.ebay.co.uk/itm/NGK-SPARK-PLUG...20d3f30958
Just looked at the quoted length they maybe too short.

[red98]

nice one soapy,must be a great feeling  :rolleyes .....love to see the video of you dancing round your bike  :lol

[Soapy]

nice one soapy,must be a great feeling  :rolleyes .....love to see the video of you dancing round your bike  :lol

Thanks red. Hope you are as lucky. If wasn't for your issue coming up on a Google search I wouldn't have got here.

[red98]

a lesson for all i think......check the easy things first 

[Soapy]

nice one soapy,must be a great feeling  :rolleyes .....love to see the video of you dancing round your bike  :lol

Thanks red. Hope you are as lucky. If wasn't for your issue coming up on a Google search I wouldn't have got here.

[Chris]

Hey Soapy, really hope that's it sorted for you mate! Send me a PM if you fancy a fazer shetland meet. haha!

Chris

[darrsi]

Stick with the one's i said as i have them on my bike and know for sure that they'll be okay.

Glad to hear you got it sussed 

[Soapy]

Stick with the one's i said as i have them on my bike and know for sure that they'll be okay.

Glad to hear you got it sussed 

Thanks darrsi. Fleabay has just been hit for 4x Caps

[Soapy]

Hey Soapy, really hope that's it sorted for you mate! Send me a PM if you fancy a fazer shetland meet. haha!

Chris

Cheers Chris
Got a wedding to go to this weekend then going South for a week. But will keep in touch.

[Chris]

[quote author=Chris link=topic=8360.msg82732#msg82732 date=1371734515]
Hey Soapy, really hope that's it sorted for you mate! Send me a PM if you fancy a fazer shetland meet. haha!

Chris

Cheers Chris
Got a wedding to go to this weekend then going South for a week. But will keep in touch.
[/quote]

Great  8)  there is a group that meets every sunday at the pier in Lerwick at 2pm and leaves at 2:30 if you'd like to go for a ride with a bigger group. I can't always make it on the sunday runs because of the shifts I work but they're a friendly bunch so go and get stuck in.

Chris

[littlejohno]

I have a similar issue to you the bike pulls fine then hits a bad spot like the fuel of spark is been turned off from around 6 to 10,000 rpm.
light throttle no issues at all and it pulls Up to 6000 fine, from cold it's much better.
And I have a ticking noise similar to a spark arking I'll be taking the leads apart shortly !!!.
Glad you sorted it

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